Oil-burning system



31,629,542 L. L. SCOTT OIL BURNING SYSTEM Filed May 31, 1924 3'Sheets-Sheet 1 May 192% L. L. sco'r'r OIL BURNING SYSTEM Filed May 31, 1924 s Sheets-Sheet 2 a 6 \W\ Z 3 $5 00 I; ii x 1 @fl I 0 i 4 J1 H W 3 0 OJ M r QJ w Q4 6 MP H 0 4 w W 1- w.

1,629 542 May 24, 1927. IL. L. SCOTT OIL BURNING SYSTEM' File y 1924 3 Sheet-Sheet 3 INVENTOH LEW/.5 L,. JQOTT Patented May 24, 1927;

UNITED STATES LEWIS L. SCOTT, OF ST. LOUIS, MISSOURI,

on ST. LOUIS, MISSOURI, A

ASSIGNOR T0 ELEGTROL INC. OF MISSOURI, CORPORATION OF MISSOURI.

OIL-BURNING SYSTEM.

Application filed-May 31 This invention relates to an improved oil burning system and various novel constructions of parts involved in said system, and has special reference to improvements in that type of oil burning fiystem described and illustrated in my pen ing application Ser. No. 538,559, filed February 23rd, 1922.

One of the objects of the invention is to provide an improved flame director for directing the flame into the furnace.

Another object is to provide anovel'construction at the entrance end of this flame director to promote intimate mixing between the air and fuel and to promote complete combustion of the fuel.

Another object of the invention is the provision of an improved safety device comprising a float adapt-ed to be operated by oil received from the flame director, if combustion fails to occur, the rise of the float acting to break the electric contacts in the motor circuit which operates the fuel pump and the fan.

Another object of the invention relates to improved means for drainin the fuel from the chamber containing the oat, and simultaneously raising the float to render the motor inoperative until the draining mechanism has been returned to normal position.

Other objects of the invention relate to details of construction and to combinations and arrangements of parts hereinafter. described and particularly pointed out in the claims.

My invention is illustrated in the accompanying drawing in which- Figure 1 is a View in front elevation of the burner proper;

Figure 2 is a view partly in side elevation and partly in section thereof; 7

Figure 3 is a top plan view of the float chamber;

Figure 4 is a transverse sectional view thereof showing its connection with the air or mixing chamber of the burner; and

Figure 5 is a diagrammatic view designed to illustrate the electrical control system employed and themanner in which the safety device operates to break the circuit to the motor in a system such as I employ.

Referring now to the drawings and particularly to Figures 1 and 2, the numeral 1 indicates a motor which operates a fan or blower 2 mounted in a fan casing 3, the latter having a spout 4 leading to an air 1924. Serial No. 717,190.

chamber 5. The shaft 6 of the motor also operates a fuel pump 7 which is designed to deliver fuel through a pipe 8 to a spray nozzle 9. Entering the air chamber 5' from the side opposite to that containing the fuel nozzle 9, is a flame director'10, hereinafter described, and suitably mounted on the lower side of the castin containing the air chamber 5 is a float ciamber 11' embodying the safety device of the invention. All these parts are suitably connected to be supported upon legs or standards 12 which may be secured at their lower ends to the floor of the furnace room.

Referring now to the flame director shown in Figure 2, the same comprises a relatively large pipe which is characterized by having a pronounced upward curve and, as shown, its outlet end is inserted in the ash door 13 of the furnace instead of in the -fire door 14 as in my prior application referred to. The inner end '15 of this pipe is formed slightly converging or funnel-shaped and projects into the air chamber 5 through an opening in the front wall of the casting 16 enclosing said chamber, and the pipe as a whole is secured to the wall of said casting by means of flanges 17 bolted to flanges 18 provided on the, said casting. Extending inwardly from the inner end of the end 15 of pipe 10 is a conical projection 19, the converging wall of which provides a circular space 20 between itself and the wall of the end 15. To permit of the escape of unburned fuel, as hereinafter explained, I drill through the wall of the end 15 on the under side thereof, a: small hole 21 which, as shown, is locatedebove the lowest level of the tube 10. Associated with the inner end of the flame director 10 1 and mounted in the, front wall 22 of chamber 5 is the spray nozzle 9 previously referred to, and a spark plug 23. Mounted on the wall 22 within the air chamber 5 is a flat plate 24, shown also in dotted lines in Figure 1, the purpose of which is to direct the air entering chamber 5 from the blower 2 through conduit at around the spark plug with such force as to prevent combustion being maintained in the immediate zone of the spark V plug, and thus prevent fouling thereof, and

also to promote the intimate mixture of the fuel and airr Assuming fuel to be sprayed through the nozzle 9 and to be ignited by the spark plug 23, the air entering the chamber .5, passing any small amount of oil accumulating in the Y tween the air and the fuel. Passing out of the inner end of the projection 19, the mixed air and fuel tend to expand and at the same time, the draft or movement of the mixture tends to produce a partial vacuum in the circular space 20 with the result that eddy currents are set up in this region, which, I find, has a very pronounced effect in promoting complete combustion of the mixture.

The end 15 could, if preferred, be made separate from the tube 10 but I prefer to make it integral therewith and thus avoid a joint which would have to be packed to prevent leakage of the fuel.

With the construction described, if the fuel should fail to ignite, the major portion of the fuel spra is thrown against the walls of the fla'me dlrectpr bythe air from the blower and will run backward due to the upward curve of pipe 10 and through the small'hole 21 into the bottom of chamber 5. Referring to Figure 4, I mount in the bottom wall of chamber 5, a-short tube 25, the upper end of which projects slightly above the floor of the chamber. The object of'having the hole 21 located above the lowest level of the pipe 10 and of having the end of the tube 25' project slightly above the floor of chamber 5 is to prevent small quantilies of fuel which maybe deposited in the bottom of tube on initially startin apparatus, from flowing into the cham er 5 and from said chamber into the float chamber.

to be subsequently referred to, and through repeated'accumulations operating the safety cut-off device when, it would be unnecessary to do so. Under the arrangement described,

. bottom of pipe 10 would be ignited or vaporized by the heat of combustion and the same would occur as to any small amount of oil accumulating in the bottom of chamber 5.

I will now describe the safety cut-oil device above referred to and the means for draining the same, referring particularly to Figure 4. Secured on the bottom of casting 16, containing the chamber 5, is a casting 26 fwhich is 'provided with a bore 27, which at one end receives the end of the tube above referred to, and at its other end communicates with a chamber 28 provided in a cylindrical casting 29, which is integral with the casting 26 -(see also Figure 3-). Mounted in the chamber 28 is a float 30 which is pro vided on its upper side with a stem 31, which is slidably mounted and guided in a bearing 32 secured in the top or cover 33 of chamber 28. Mounted in the cover. 33 is a contact screw 34 having at its upper end a contact 35, and having a conductor 36 connected with its tower end.w Mounted in the cover 33 the.

is also a second contact screw 37 having a conductor 38 connected 'to'its lower end. Connected at one end to the contact screw 37 is a curved spring metal contact arm 39 which is in normal engagement with the contact and is provided at its outer end and on its underside with an insulating block 40 to beengaged by the upper end of stem 31 when the float rises, to lift the arm 39 out of engagement with the contact 35 and thus break the circuit to the motor, as hereinafter described. The parts just described are normally covered by a cap 41 pivotally mounted at 42 on the wall of casting 29 andyieldably held closed by means .of a spring arm 43. i

Assuming the device to have been placed 1n operation and ignition not to have oc curred, the fuel, as before stated, will flow backward in the pipe 10 and out through openlng .21 into the air chamber 5, thence through tube 25 and bore 27 into chamber 28, causing the float 30 to rise and its stem to. lift the arm 39. Assuming, further, that the cause which had prevented ignition has been remedied, it will next be necessary to drain the oil from chamber 28. The construction for effecting this'will now be de-- scribed, referring particularly to Figures 1, 3 and 4.

Rotatably mounted in a stuffing box 44 provided in the wall of the casting 29 is a of the recess49, and I insert through an opening in the extension 48 adjacent to the side of the wall of casting 29, through which it enters, a cotter pin, or the like, 53, whereby the tube 45 cannot be moved inward or pulled out. The "bottom of the float 30 normally rests upon the flat sides 50 of the extension 48, as shown. To drain the chamber 28, the dust cap 47 is removed from the .upper end of extension 46 and the latter is turned downward, rotating-tube 45 in the stuffing box. This brings the upper end of extenslon 46 below the level of the oil in the chamber 28, which accordingly flows out of tube 45.- In turning tube 45, the under rounded side of extension 48 will be turned upward, 'so that as the oil flows out of the chamber, the float 30 cannot return to its lowermost position on the floor of chamber 28, but will be held elevated to hold contact arm 39 out of engagement with the contact 35. This feature constitutes an additional safety means, for, should a careless person iao cam surface, with the underside of float 30.

Otherwise, as will be clear, should, the burner be placed in operation and if ignition did not occur, the fuel passing into the chamber. 28 will not operate the float, but will continue to flow out through the tube 45.

T will now briefly describe the electnical wiring and controlling mechanism, and particularly with reference to the cutting out of the motor'through the rise of the float 30. The electrical control mechanism is located in a casing 54 (Figures 1 and 2) and is shown diagrammatically in Figure 5, the

relative location of the parts, however, not being preserved, owing to the nature of the View. Entering the control box 54 are two main line wires or conductors 55 and 56, which are connected to a transformer 57. The wire 56 also leads to the motor 1 and to a transformer 58 and thence back to the motor. A branch wire 59 connects wire 56 with a contact screw 60, mounted on an insulating board in the usual way within the control box 54. The wire 55 leads to a similar contact screw 61. From the low-voltage side of transformer 58 a wire 62 leads to a spark coil 63, from the secondary winding of which a wire 64 leads to the spark plug 23, previously referred to, the latter being grounded at 65. A second wire 66 leads from the low-voltage side of the transformer to a flexible contact member 67,

which is adapted to be moved by the cooling of a thermostatic bar 68 into engagement with a contact screw 69. From the low-voltage side of transformer 57, a wire 70 leads to a coil 71 surrounding the thermostatic bar 68, and thence to a contact plate 72 with which the upper end of the thermostatic bar 68 is electrically connected. The other" wire from the transformer, heretofore indicated by the numeral 38 in Figure 4, leads to the contact screw 37 and is thus electrically con-- nected with the spring arm 39, and has interposed in its length a thermostatic switch 73. The wire '36, also previously referred to, leads from the contact screw 34 to the coil 74 of an electro-magnet 75, thence to the contact screw 69. The electro-magnet 75 is adapted to actuate an armature 76 on which is mounted atmercury tube switch 77, the mercury in which is adapted to close and open the contacts 78 connected by conductors 79 with the contact screws 60 and 61, previously referred to, and thus control the circuit to the motor. The armature 76 .is pivotally mounted at 80 through the medium of'an arm 81, which is electrically connected with a spring switch member 82 mounted on the underside of the armature.

Leading from the arm 81 is a wire 83 which passes to a contact screw 84 grounded at 85.

The thermostat 73 is located in the room whose temperature is tobe controlled, and when this temperature falls below a given degree, it moves to close the circuit over the wire 38. Thence the circuit is completed over the arm 39, contact 35 and wire 36 to the electro-magnet 75. In its normal or cooled condition, the thermostatic bar 68 occupies a position to the left of that shown in Figure 5 in which the contacts 69, 67 and 68 are in engagement. Hence the magnet will be energized and draw downward the armature 76 tilting the mercury in tube 77 to the right to close contact 78 whereby the circuit to the motor will be closed and the burner placed in operation. Contact between the bar 68 and the contact 67 places the spark plug circuit in condition to be closed when the circuit to the motor is closed.

The current passing through coil 71 beats .net, a parallel circuit is closed over the switch arm 82 and wire 83 and this parallel circuit maintains the electro-magnet energized so that the burner will continue to operate. Should the main line circuit over the wires 55 and 56 he suddenly turned oif and y operation to supply fuel, the latter, for some reason or other, should not be ignited by the spark plug. In this case the unignited fuel, as previously explained, will flow into the float chamber 28 and cause the float 30mg, rise so that the stem 31-will engage the arm 39 and raise thesame, thereby breaking the circuit over the wire 38 and consequently breaking the circuit to the motor. The operation of the apparatus would then instantly cease. The same result occurs when.

the extension 46 of tube 45 is turned downward, in which event the float 30 is mechanically raised to break the circuit over the wire 38 to the thermostat.

Tn prior constructions embodied in various applications of mine now pending, the spray nozzle 11 was located at the end of a conical i projection which extended, in some mstances, almost into .:the entrance end of the flame director. In the present case, and as shownby Figure 2, the nozzle 9 projects only slightly beyond the front wall of the air openings to said pipe, thus heating the same and facilitating the vaporization and com bustion of the liquid fuel. In addition, the space provided gives full opportunity for circulation and intimate mixture of the air admitted to chamber 5 with the fuel sprayed therein:

I claim: v

1. In an oil burning system of the class described, in combination with a chamber for receiving unignited oil, a float in said chamber, and a cut-out device adapted to be actuated onthe rise of said float, to stop the operation of the system, means for draining said chamber comprising a tube rotatably mounted in the wall of said chamber, having an upward extension outside of the chamber and carrying a cam member projecting into the chamber and located beneath said float, whereby, upon turning said extension downward to drain the chamber, said tube will be rotated to cause the cam member to raise said float and thereby systems, comprising a chamber adapted to I receive delivered oil upon failure of igni-.

tion, a float in said chamber, a cut-out controlling the operation of the system and" adapted to be operated on rise of the float to stop the operation of the system, and means for draining said chamber comprising a tube rotatably mounted in the wall thereof and having a substantially semi-cylindrical ex tension projecting under the bottom of said float with its flat edges engagingsaid bottom, and an upward extension located out-- side of the chamber, whereby, upon turning said extension downward to drain the chamber, the rounded portion of said,extension will be turned upward against the bottom of the float and cause the same to rise to actuate said cut-out or, if the float is in an 7 elevated position, due to liquid in said chamber, will prevent the return of the float to normal position until said extension has been turned upward again.

- In testimony whereof, I have hereunto set my hand.

LEWIS L. SCOTT. 

